Objective:To investigate the effect of pressurization on the recovery of exercise-induced fatigue in rats in plateau environment.Methods:A total of 24 rats in natural environment were transported from altitude of 1 520 m to 2 260 m, then randomly divided into three groups: group A (quiet control group), group B (natural recovery group), and group C (pressurized recovery group), with 8 rats in each group. After the exercise fatigue model training on the running platform every day, the rats in the group B recovered naturally, while the rats in the group C had a 1-hour-recovery in a pressurized cabin of 0.2 MPa for 6 days. On the day 7, the rats in the group B and the group C exercised to exhaustion, and then were killed 24 hours later for sampling. The exercise time of exhaustion was recorded; gastrocnemius HIF-1α, lung iNOS, myocardial CaMKⅡ, and BNP protein expressions, and serum SOD, TAOC, GSH-Px and CAT, ROS, MDA concentration were determined; the morphological chages of myocardium after HE staining, and gastrocnemius were observed.Results:(1) The exhaustive exercise time of the group B (99.00±69.37 min) was lower than that of group C (126.14±59.09 min). (2)The expression level of HIF-1α protein in skeletal muscle was 0.220±0.170 in the group A, 0.070±0.003 in the group B, and 0.360±0.140 in the group C. The expression level of the group C was significantly higher than that in the group B ( P<0.05). The expression level of CaMKⅡ protein in myocardium was 1.18±0.17 in the group A, 1.07±0.13 in the group B, and 1.40±0.22 in the group C. There were no statistical difference between each group. The expression level of BNP protein in myocardium was 0.29±0.05 in the group A, 0.29±0.08 in the group B, 0.53±0.01 in the group C. There were significant differences comparing the group C with the group A and the group B respectively ( P<0.01). The expression level of iNOS in lung was 0.130±0.002 in the group A, 0.450±0.004 in the group B, and 0.360±0.005 in the group C. It was significantly lower in the group A than those in the group C and the group B ( P<0.01). (3) Compared with the group A, the serum SOD ( P<0.05) and GSH-Px decreased, ROS and MDA increased in the group B ( P<0.05). Compared with the group B, the serum SOD ( P<0.05), GSH-Px and TAOC increased, ROS and MDA decreased in the group C ( P<0.05). (4) Under light microscope, muscle fiber in the group B showed atrophy, thinning, rupture, increase of cell gap, and local lytic necrosis; while muscle fiber in the group C showed shrinking gap, decreased rupture, and relieved cell infiltration. Conclusion:In the plateau and hypoxia environment, the application of pressurization to the rats in exercise-induced fatigue can prolong the exhaustive exercise time, alleviate the morphological changes of muscle fibers in myocardium and skeletal muscles, e. g. thinning, rupture, and increase of cell gap, enhance the expressions of HIF-1α, CaMKⅡand BNP in gastrocnemius muscle, increase the levels of serum SOD, GSH Px, and TAOC, reduce the levels of serum ROS and MDA, and contribute to sports fatigue recovery.

Objective:To investigate the effect of pressurization on the recovery of exercise-induced fatigue in rats in plateau environment.Methods:A total of 24 rats in natural environment were transported from altitude of 1 520 m to 2 260 m, then randomly divided into three groups: group A (quiet control group), group B (natural recovery group), and group C (pressurized recovery group), with 8 rats in each group. After the exercise fatigue model training on the running platform every day, the rats in the group B recovered naturally, while the rats in the group C had a 1-hour-recovery in a pressurized cabin of 0.2 MPa for 6 days. On the day 7, the rats in the group B and the group C exercised to exhaustion, and then were killed 24 hours later for sampling. The exercise time of exhaustion was recorded; gastrocnemius HIF-1α, lung iNOS, myocardial CaMKⅡ, and BNP protein expressions, and serum SOD, TAOC, GSH-Px and CAT, ROS, MDA concentration were determined; the morphological chages of myocardium after HE staining, and gastrocnemius were observed.Results:(1) The exhaustive exercise time of the group B (99.00±69.37 min) was lower than that of group C (126.14±59.09 min). (2)The expression level of HIF-1α protein in skeletal muscle was 0.220±0.170 in the group A, 0.070±0.003 in the group B, and 0.360±0.140 in the group C. The expression level of the group C was significantly higher than that in the group B ( P<0.05). The expression level of CaMKⅡ protein in myocardium was 1.18±0.17 in the group A, 1.07±0.13 in the group B, and 1.40±0.22 in the group C. There were no statistical difference between each group. The expression level of BNP protein in myocardium was 0.29±0.05 in the group A, 0.29±0.08 in the group B, 0.53±0.01 in the group C. There were significant differences comparing the group C with the group A and the group B respectively ( P<0.01). The expression level of iNOS in lung was 0.130±0.002 in the group A, 0.450±0.004 in the group B, and 0.360±0.005 in the group C. It was significantly lower in the group A than those in the group C and the group B ( P<0.01). (3) Compared with the group A, the serum SOD ( P<0.05) and GSH-Px decreased, ROS and MDA increased in the group B ( P<0.05). Compared with the group B, the serum SOD ( P<0.05), GSH-Px and TAOC increased, ROS and MDA decreased in the group C ( P<0.05). (4) Under light microscope, muscle fiber in the group B showed atrophy, thinning, rupture, increase of cell gap, and local lytic necrosis; while muscle fiber in the group C showed shrinking gap, decreased rupture, and relieved cell infiltration. Conclusion:In the plateau and hypoxia environment, the application of pressurization to the rats in exercise-induced fatigue can prolong the exhaustive exercise time, alleviate the morphological changes of muscle fibers in myocardium and skeletal muscles, e. g. thinning, rupture, and increase of cell gap, enhance the expressions of HIF-1α, CaMKⅡand BNP in gastrocnemius muscle, increase the levels of serum SOD, GSH Px, and TAOC, reduce the levels of serum ROS and MDA, and contribute to sports fatigue recovery.